I upgraded the firmware hc05, I think we've succeeded! But now I'm able to send any AT command! When I turn on the module, the LED blinks, detect the bluetooth module for the PC! I'm sending the command AT \ r \ n, it returns nothing!I noticed something when I turn on the module with the pin 34 high LED flashes more slowly! Can you help me?Thank you!

- Is it possible to pair with PC via Bluetooth and use AT commands to control GPIO (PIO pins) remotely?

I'm asking it because I don't want to use it just like a BT/Serial interface, if I have remote GPIO access I can control external things directly from an Android phone without using a microcontroller in the other end to control devices.

In fact the CSR chip is already an uC, then I can use its GPIO to control anything, but I don't know if the firmware allow me to do it remotely. I think these AT commands to control PIO pins needs to be executed locally (over serial), but maybe I can control it over BT connection as well.

I'm also an embedded system developer with Linux (uClinux) background and a little bit of RTOS (mainly NuttX). I just received my Bluetooth module (from dealextreme) yesterday night.I read the manual but didn't see nothing about remote AT commands.

Hi Byron, great work. Just a question. You say: "Then the module will enter on AT mode without your configured baud rate" (regarding the first way to get into AT mode)I understand from the datasheet however that if you choose that option you actually get in on AT mode WITH the configured baudrate.Am I wrong or is it just a type?

hi Byroni have a module blue tooth, when i power it, it automatic into work mode, pin32 high level before paired, after paired, it get low level. i can't force it into AT command mode although i did 2 way u decribed. i don't receive "OK" when i send AT\r\n commandThanks

Hello, kinda new to this, not sure what you mean by "set low level and high level" ? Is that GND and the 3.3V cables ?So i touch pin34 with ground cable, keep it there, bring power to the chip, then touch pin34 with a 3.3 V ?Won't that make an electric short circuit?thanks

1) at some point in the communication process the HC-05 is "INQUIRING". I thought I could stop this mode with the command "AT+INQC" but when I check the state, I am still inquiring. 2) the only way I can leave that mode is to "pair" the HC-05 with my PC. I am able to "pair" the HC-05 with my PC (running window 8)I check the state and it confirms they are paired. I belive I need to connect next. So I issue the command "AT+LINK=". I get FAIL. I can't get past this point. Can you help? provide some step by instructions (along with when I should or should not key the HC-05) to help me get connected? Is there a potential problem Windows 8? Thoughts on why I continue to receive the "FAIL" message? Thanks...

I looks as if you are not following this blog very closely, but just in case you come back or another reader has info:

Is there any way to send commands or serial data to and from the module using the SPI port rather than the UART? The reason is that in some applications it is not possible to match higher async baud rate, eg: for ATMega chip at 16 MHz the highest standard UART rate which works may be 115,200 bps, tho the module is capable of much more. So if I could send/receive serial data via the SPI port, it would be very helpful.

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hi guys i have HC-05 bluetooth. i wanted to control device. i check HC-05 that connect to PC by USB serial converter. i can send AT in command mode and return ok and i did the set. it is okey. BUT i can't return to DATA mode. i did disable key pin and reset power. did things i could . spent many time over that. pls help me

Hi, Does anyone know how to get the 'connected' LED to go on? I don't need to communicate at all - all I want to do is to detect that someone has connected to the HC-03, and turn a light on. I can do that with the 'connected' light, but it never goes on. I've got it upgraded, and can see the 'paired' LED go on when I pair with it. My android also never goes into 'connected' mode either. Do I need to put a ucontroller on the serial line? And/or what does it need to do?

I have purchased some inexpensive hc-06 modules from Aliexpress. They are advertised as hc-06, and the PC detects it as the name hc-06. I can pair and connect to the module over bluetooth (using the default 1234 pin). I can the send data in both directions, at 38400 baud. While it is connected, the red led goes off for 2 seconds, then does 2 quick flashes, then off for 2 seconds, and this repeats.

When not connected over bluetooth, the red flashes rapidly. My problem is that I cannot get any of the AT commands to respond. I type AT and I never get the OK response. I have tried different baud rates. I'm not sure what else to try. Has anyone gotten a module with firmware like this, that blinks the red led while in bluetooth connection? I need to figure out how to configure these modules.